package com.tonghl.juc.lock_study.code;

import java.util.concurrent.locks.Condition;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;

/**
 * Created by tonghl
 * 1.题目：synchronized和lock有什么区别？用新的lock有什么好处？举例说说
 *        1.原始构成
 *        synchronized是关键字属于JVM层面
 *              monitoernter(底层是通过monitor对象来完成，其实wait/notify等方法也是依赖monitor对象只有在同步快或者方法则才能调用wait/notify等方法)
 *              monitorexit
 *        Lock是JDK1.5才出现的类，是api层面的
 *        2.使用方法
 *        synchronized是不需要用户手动释放的，当synchronized代码执行完成后系统会自动释放对锁的占用
 *        ReentrantLock则需要用户手动释放锁，若没有主动释放，可能会造成死锁的现象
 *        需要lock()和unlock()方法配合try/finally语句来完成
 *
 *        3.等待是否可中断
 *         synchronized不可中断，除非抛异常或者正常运行
 *         ReentrantLock 可中断，1.设置超时方法trylock(Long timeout,Long unit)
 *                              2.LockInterruptibly（）放代码块中，调用interrupt()方法可中断
 *        4.加锁是否gongp
 *        synchronized非公平锁
 *        ReentrantLock两者都可以，默认是非公平锁，构造方法可以传入boolean值，true为公平锁，false为非公平锁
 *
 *        5.锁绑定多个条件Condition
 *        synchronized没有
 *        ReentrantLock用来实现分组唤醒需要唤醒的线程们，可以精确的唤醒，而不是像synchronized要么随机唤醒一个线程要么唤醒全部线程
 * ===================================================================================================================
 * ===================================================================================================================
 * ===================================================================================================================
 *
 * 题目：多线程间按调用顺序，实现A->B->C三个线程启动，要求如下
 * AA打印5次，BB打印10次，CC打印15次
 * 紧接着
 * AA打印5次，BB打印10次，CC打印15次
 * ......
 * 来10轮
 *
 */

class ShareData{
    private  int number=1;//A :1   B;2    C:3
    private Lock lock=new ReentrantLock();
    private Condition c1=lock.newCondition();
    private Condition c2=lock.newCondition();
    private Condition c3=lock.newCondition();
    public void print5(){
        lock.lock();
        try {
            //1.判断
            while (number!=1){
                c1.await();
            }
            //2 干活
            for (int i = 1; i <=5 ; i++) {
                System.out.println(Thread.currentThread().getName()+"\t"+i);
            }
            //3 通知
            number=2;
            c2.signal();

        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            lock.unlock();
        }
    }

    public void print10(){
        lock.lock();
        try {
            //1.判断
            while (number!=2){
                c2.await();
            }
            //2 干活
            for (int i = 1; i <=10 ; i++) {
                System.out.println(Thread.currentThread().getName()+"\t"+i);
            }
            //3 通知
            number=3;
            c3.signal();

        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            lock.unlock();
        }
    }

    public void print15(){
        lock.lock();
        try {
            //1.判断
            while (number!=3){
                c3.await();
            }
            //2 干活
            for (int i = 1; i <=15 ; i++) {
                System.out.println(Thread.currentThread().getName()+"\t"+i);
            }
            //3 通知
            number=1;
            c1.signal();

        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            lock.unlock();
        }
    }


}

public class SyncAndReentrantLockDemo {

    public static void main(String[] args) {

        ShareData shareData=new ShareData();
         new Thread(()->{
             for (int i = 1; i <=10; i++) {
                shareData.print5();
             }
         },"A").start();

        new Thread(()->{
            for (int i = 1; i <=10; i++) {
                shareData.print10();
            }
        },"B").start();

        new Thread(()->{
            for (int i = 1; i <=10; i++) {
                shareData.print15();
            }
        },"C").start();

    }


}
